Means for preventing condensation on transparent partitions between regions of different temperature



1,725,664 EliARTITIONS NT TUR AL RANSPAR ERA MITCHELL ET VENTINGCONDENSATION OF DIFFE T TEMP Filed OCB. 11, 1928 Fvgfi. b

WEEN REGIONS 5 FOR PRE BET ll l

Aug. 20, l 92 9.

MEAN

/ ATTORNEYS Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

' RAYMOND JAMES MITCHELL, OE TAPLOW, AND ARTHUR THOMAS HAWKINS, OELONDON, ENGLAND, AssIGNoRs To FRIGIDAIRE CORPORATION, OF DAYTON, OHIO,

A CORPORATION OF DELAWARE.

MEANS FOR PREVENTING cOND NsATIoN N TRANsr R NT PARTITIoNs BETWEENEeIoNs OF DIFFERENT TEMr nATURE.

Application filed October 11, 1928, S er1a1 No. 311,923, and in GreatBritain Octoberfi, 1927.

The present invention relates to a means for preventing condensation ofmoisture on transparent partitions separating regions of differenttemperatures. The invention is 5 particularly adapted for use withshow-cases,

counters and the like in' which goods are displayed in a chambermaintained at a low temperature, and is also suitable for the doors ofrefrigerators and cold-storage cupboards. If a single sheet of glass isemployed, moisture will condense on the outside and the view of theinterior will be obscured. Further, if a I double thickness of glass isemployed, having an intervening, insulating air space, moisture willcondense on the outermost face of the inner sheet of glass. It is theobject of the present invention to overcome these difficulties and toprovide a transparent partition or window which will remain clear underconditions of use. 1

According to the present invention we provide a means for preventingcondensation on transparent partitions between regions of differenttemperatures, comprising two or more sheets of glass separated by layersof substantially dry air or by evacuated zones. According to the presentinvention also we provide a method of constructing a transparentpartition which consists in forming the partition of a frame containingtwo or more sheets of glass which form with the frame one or moreair-tight compartments. A zone or layer of dry air is contained betweensheets of glass which are spaced apart, being secured at their edges ina frame so as to confine an air-tight space.

A particular embodiment of the invention as applied to a singletransparent door, window or panel will be described by Way of examplewith reference to the accompanying drawings, although of course anynumber of such panels might be assembled and used to constitute any orall of the walls of a coldstorage chamberor show-case.

In the accompanying drawings: Figure 1 is a front elevation of a portionof'transparent window or panel; Figure 2 is a section of the line 22 ofFigure 1.

Figure 3 is asectional view similar to Figure 2 showing how the panel isset in the frame of a show-case or the like.

The panel consists of' a Wooden frame 1, comprising front and rearportions 2 and 3, the front portion being provided with a flange 4,which co-operates with the projecting part of the rear portion 3, toform a clamping device for the seating 5 for the sheets of glass. Theseating 5 consists in this instance-of rubber blocks 6' grooved" as at 7to receive the edges of the sheets of glass 8 of which three are in thisinstance employed. The rubber blocks may extend throughout the wholelength of one side of the panel or any convenient number of blocks ofsuitable length may be employed. The rubber blocks are of suchdimensions that, when the rear portion 3 of the frame is clampedor'screwed on to the front portion, the rubberis compressed and so formsa tight joint with the glass. If desired, rubber or like cement may beapplied to'the outer walls of the rubber blocks and in the grooves whichreceive the edges of the glass sheets for the purpose of ensuring aleak-proof and absolutely air-tight assembly. Apertures 9 are providedextending through the wood and rubber portions of the frame throughwhich the air can be extracted from the space between two sheets ofglass after which it may if desired be replaced by .air which has beendried and/or treated chemically. Alternatively the spaces may of coursebe left in an evacuated condition. The apertures may consist of metaltubes which may or may not project beyond the frame and are internallyor externally threaded to facilitate connection to an air pump or thelike, and to facilitate air-tight closure by a plug or cap as forinstance by the plug 10.

In Figure 3 We have shown the preferred method of securing an assembledpanel in a show-case for example. In this figure 11 represents the frameof the show-case which is provided with a recess 13 adapted toaccommodate the frame of the assembled panel with a tight fit both thepanel 1 and the frame 12 being very carefully made for this purpose.Preferably beading or moulding is secured over the joint between theframe of the assembled panel and the frame 11 of the show-case at thefront and if desired at the rear also..

WVhilst we have hereinbefore described one embodiment of the invention,it must be understood that modifications may be m'ade without departingfrom the scope of the invention. For example the frame may. be

made of. metal or any desired material, and

any suitable form of packing might be employed instead of the channelsection or grooved rubber blocks described above. Further, the inventionmay be applied to doors, windows, partitions or the like which may bemade of any desired number of sections.

What we claim is 1. Means for preventing condensation on transparentpartitions between regions ofdifl'erent temperature comprising atleasttwo sheets of transparent glass, separate blocks of compressibleair-impervious material for each sheet provided with grooves for housingthe marginal edges of the said sheets,

a frame for housing said sheets and said blocks and means for clampingsaid blocks together thereby to form an airtight space .between eachpair of glass sheets.

2. A case having a transparent partition comprising a frame providedwith a flanged recess, a transparent panel comprising at least twosheets of transparent glass, a anel element surrounding the edges ofsaid s eets, a construction of compressibleair-impervious materialinterposed between the edges of said sheets and said panel element, saidcon- 7 struction including a separate block of compressibleair-impervious material provided with a groove for each sheet of glass,and

-means for securing said panel element in said flanged recess.

3. A case having a transparent partition comprising a frame providedwith a flanged recess, a transparent panel comprising at least twosheets of transparent glass, a panel element surrounding the edges ofsaid sheets, a construction of compressible air-impervious materialinterposed between the edges of said sheets and said panel element, saidconstruc tion including a separate block of compressible air-imperviousmaterial provided with a groove for each sheet of glass, one edge ofsaid panel element and one edge of said frame being in alignment andbeading-securing said panel to said frame.

4. Means for preventing condensation on transparent partitions betweenregions of different temperatures comprising a plurality of spacedsheets of transparent material, retaining means. for the margins of thesheets comprising a body of compressible, air-imper vious materialhaving grooves receiving the RAYMOND JAMES MITCHELL. ARTHUR THOMASHAWKINS.

